/* Naive insertion sort. Performance doesn't matter here. */
static void sym_insert(BuildCtx *ctx, int32_t ofs,
const char *prefix, const char *suffix)
{
ptrdiff_t i = ctx->nsym++;
while (i > 0) {
if (ctx->sym[i-1].ofs <= ofs)
break;
ctx->sym[i] = ctx->sym[i-1];
i--;
}
ctx->sym[i].ofs = ofs;
ctx->sym[i].name = sym_decorate(ctx, prefix, suffix);
}
/* Collect external relocations. */
static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type)
{
if (ctx->nreloc >= BUILD_MAX_RELOC) {
fprintf(stderr, "Error: too many relocations, increase BUILD_MAX_RELOC.\n");
exit(1);
}
if (relocmap[idx] < 0) {
relocmap[idx] = ctx->nrelocsym;
ctx->relocsym[ctx->nrelocsym] = sym_decorate(ctx, "", extnames[idx]);
ctx->nrelocsym++;
}
ctx->reloc[ctx->nreloc].ofs = (int32_t)(addr - ctx->code);
ctx->reloc[ctx->nreloc].sym = relocmap[idx];
ctx->reloc[ctx->nreloc].type = type;
ctx->nreloc++;
return 0; /* Encode symbol offset of 0. */
}
/* Build the machine code. */
static int build_code(BuildCtx *ctx)
{
int status;
int i;
/* Initialize DynASM structures. */
ctx->nglob = GLOB__MAX;
ctx->glob = (void **)malloc(ctx->nglob*sizeof(void *));
memset(ctx->glob, 0, ctx->nglob*sizeof(void *));
ctx->nreloc = 0;
ctx->globnames = globnames;
ctx->relocsym = (const char **)malloc(NRELOCSYM*sizeof(const char *));
ctx->nrelocsym = 0;
for (i = 0; i < (int)NRELOCSYM; i++) relocmap[i] = -1;
ctx->dasm_ident = DASM_IDENT;
ctx->dasm_arch = DASM_ARCH;
dasm_init(Dst, DASM_MAXSECTION);
dasm_setupglobal(Dst, ctx->glob, ctx->nglob);
dasm_setup(Dst, build_actionlist);
/* Call arch-specific backend to emit the code. */
ctx->npc = build_backend(ctx);
/* Finalize the code. */
(void)dasm_checkstep(Dst, -1);
if ((status = dasm_link(Dst, &ctx->codesz))) return status;
ctx->code = (uint8_t *)malloc(ctx->codesz);
if ((status = dasm_encode(Dst, (void *)ctx->code))) return status;
/* Allocate symbol table and bytecode offsets. */
ctx->beginsym = sym_decorate(ctx, "", LABEL_PREFIX "vm_asm_begin");
ctx->sym = (BuildSym *)malloc((ctx->npc+ctx->nglob+1)*sizeof(BuildSym));
ctx->nsym = 0;
ctx->bc_ofs = (int32_t *)malloc(ctx->npc*sizeof(int32_t));
/* Collect the opcodes (PC labels). */
for (i = 0; i < ctx->npc; i++) {
int32_t ofs = dasm_getpclabel(Dst, i);
if (ofs < 0) return 0x22000000|i;
ctx->bc_ofs[i] = ofs;
if ((LJ_HASJIT ||
!(i == BC_JFORI || i == BC_JFORL || i == BC_JITERL || i == BC_JLOOP ||
i == BC_IFORL || i == BC_IITERL || i == BC_ILOOP)) &&
(LJ_HASFFI || i != BC_KCDATA))
sym_insert(ctx, ofs, LABEL_PREFIX_BC, bc_names[i]);
}
/* Collect the globals (named labels). */
for (i = 0; i < ctx->nglob; i++) {
const char *gl = globnames[i];
int len = (int)strlen(gl);
if (!ctx->glob[i]) {
fprintf(stderr, "Error: undefined global %s\n", gl);
exit(2);
}
/* Skip the _Z symbols. */
if (!(len >= 2 && gl[len-2] == '_' && gl[len-1] == 'Z'))
sym_insert(ctx, (int32_t)((uint8_t *)(ctx->glob[i]) - ctx->code),
LABEL_PREFIX, globnames[i]);
}
/* Close the address range. */
sym_insert(ctx, (int32_t)ctx->codesz, "", "");
ctx->nsym--;
dasm_free(Dst);
return 0;
}
